The Legend of Zelda: The Wind Waker - Morth

Morths are tiny balls that have an eyeball on them, as well as spikes protruding from their bodies. They cannot cause Link any harm, but they will swarm him and latch onto his body, essentially slowing him down and making it so he can't jump as high. They can be found in forested areas, as well as spawned by Mothulas. Morths can be easily dispatched by rolling or a spin attack, should they be stuck to Link. One extra note is that Morths can float on water, so Link needs to be extra careful with that piece of knowledge.